One of the key components of any computer system is a place to store data Computer systems have many different places where data can be stored. One common place for storing massive amounts of data in a computer system is on a disc drive. The most basic parts of a disc drive are a disc that is rotated, an actuator that moves a recording/playback transducer to various locations over the disc, and electrical circuitry that is used to write and read data to and from the disc. The disc drive also includes circuitry for encoding data so that it can be successfully retrieved and written to the disc surface. A microprocessor controls most of the operations of the disc drive as well as passing the data back to the requesting computer and taking data from a requesting computer for storing to the disc.
The transducer is typically housed within a small ceramic block. The small ceramic block is passed over the disc in a transducing relationship with the disc. The transducer can be used to read information representing data from the disc or write information representing data to the disc. When the disc is operating, the disc is usually spinning at relatively high revolutions per minute ("RPM").
These days common rotational speeds are 7200 RPM. Some rotational speeds are as high as 10,000 RPM. Higher rotational speeds are contemplated for the future. These high rotational speeds place the small ceramic block in high air speeds. The small ceramic block, also referred to as a slider, is usually aerodynamically designed so that it flies over the disc. The best performance of the disc drive results when the ceramic block is flown as closely to the surface of the disc as possible. Today's small ceramic block or slider is designed to fly on a very thin layer of gas or air. In operation, the distance between the small ceramic block and the disc is very small. Currently, "fly" heights are only a few micro inches.
Information representative of data is stored on the surface of the memory disc. Disc drive systems read and write information stored on tracks on memory discs. Transducers, in the form of read/write heads, located on both sides of the memory disc, read and write information on the memory discs when the designated transducer is accurately positioned over the designated track on the surface of the memory disc. The transducer is also said to be moved to a target track. As the memory disc spins and the read/write head is accurately positioned above a target track, the read/write head can store data onto a track by writing information representative of data onto the memory disc. Similarly, reading data on a memory disc is accomplished by positioning the read/write head above a target track and reading the stored material on the memory disc. To write on or read from different tracks, the read/write head is moved radially across the tracks to a selected target track. The data is divided or grouped together on the tracks. In some disc drives, the tracks are a multiplicity of concentric circular tracks. In other disc drives, a continuous spiral is one track on one side of a disc drive. Servo feedback information is used to accurately locate the transducer. The actuator assembly is moved to the required position and held very accurately during a read or write operation using the servo information. It should be noted that the tracks on a disc drive are very thin and closely spaced. Currently, track densities are greater than 10,000 tracks per inch. In practical terms, this means that there are as many as 12 tracks across the width of a single human hair. Of course, track densities will increase in the future.
In the past, the spindle or hub was mounted to the base or deck of the disc drive. The spindle included electrical contacts which formed electrical connections to the windings of the motor and possibly the center tap of the motor. The motor is commutated to spin the spindle and the attached hub. One or more discs are attached to the hub. A flex cable was used to connect the electrical contact pads on the spindle to the printed circuit board external to the disc enclosure. In some instances the deck included a special throughway that provided a sealed connection to the printed circuit board. The flex cable is long, and cumbersome in terms of manufacture. In addition, connector and seal through the base or deck of the disc drive is another special part which adds inventory during manufacture and which makes assembly more complex.
Some disc drives have replaced the spindle motor pads with pins that can be accessed with another connector that directly connects to the printed circuit board on the outside of the disc enclosure. In the past, these have been difficult to align and many times, during manufacture, the pins associated with the spindle or the connector to which the pins attach may become damaged. Both may also become damaged. In addition, the solder joints were the only means for holding the connector to the printed circuit board. In the presence of shock loading to the connector, the solder joints may break free and the disc drive would fail. There is also need for non-standard hardware that would cost more than a standard screw type fastener. A spanner type or flat nut is needed to hold the spindle of the in-hub motor in place. This special part costs much more than a standard connector. In addition, the spanner nut also tended to gall the deck as it was tightened. Galling caused the torque necessary to tighten the part to read high. When robots are used to attach the spindle to the base or deck of the disc drive, the robots tighten to a specified torque. With galling, the torque may be reached before the spindle is truly tightened.
To lessen the problems associated with previous spindle motor to printed circuit board connectors, there is a need for a connector which can directly connect the spindle motor to the printed circuit board. There is also a need for a connector which does not require accurate alignment. In other words, the connector should be more forgiving so that it can tolerate slight misalignments without damaging the printed circuit board or the electrical connectors of the spindle motor. What is also needed is a connector that resists breaking solder joint connections when the connector undergoes a shock loading event. Also needed is a reliable electrical connection so that the disc drive is also reliable.